Binding referendum requires implementation by constitutional amendment.
Consultative Referendum can anyhow be held if ordered by ad-hoc-law.

PROCEDURE

In
accordance with Art 73 (1), the government has to consult the Council
of State, who has to provide a recommendation which of the paragraphs
to be applied. In constitutional practice, this recommendation is
binding for the government. The government followed the recommendation
of the Council of State to apply Art. 91 (1) for the ratification
of the Amsterdam Treaty (Kammerstukken Nr. 25922). On 5 November
1999, the Tweete Kamer (lower house) approved the bill with more
than 80% of the votes in favor. On 22 December, the Eerste Kamer
(upper house) gave its assent also with more than 80% of the votes
in favor and ratification went into effect on 24 December.